Self-locating door interlock apparatus and enclosures, assemblies, and methods including same

ABSTRACT

A door interlock apparatus is disclosed. The door interlock apparatus has a body configured to couple to a first one of a door and an enclosure structure, the body having one or more angled self-locating features, a locking protrusion extending from a surface of the body and configured to couple with the locking member of an interlock mechanism, and a misalignment-accommodating mechanism configured and adapted to allow motion of the body. The door interlock apparatus aligns the locking protrusion and locking member during door closing, even when the door and enclosure structure are substantially misaligned. Electrical component enclosures, door interlock assemblies, and methods of assembling a door interlock assembly are also provided, as are other aspects.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/655,820 filed on Jun. 5, 2012, entitled “Self-Locating DoorInterlock,” and is a divisional of Pending patent application Ser. No.13/623,608, the disclosures of which are hereby incorporated byreference in its entirety.

FIELD

The invention relates generally to door interlock apparatus, and moreparticularly to door interlock apparatus for electrical componentenclosures.

BACKGROUND

Switchboards, panelboards, and motor controller enclosures having one ormore access doors may include electrically-energized components therein.UL 347 specifies that mechanical interlocks should be provided oncertain of these enclosures in order to prevent operators from openingsuch equipment access doors when the equipment being protected is stillelectrically energized. This minimizes safety hazards to the operators.

In conventional mechanical interlocks used in the past to accomplish alocking function on such doors, a locking protrusion (pin) has beenwelded directly to the door. This locking protrusion interfaces with aconventional door interlock mechanism. However, because all doors arenot perfectly manufactured or assembled, the mechanical interlock maynot always function properly.

Accordingly, a need exists to improve the mechanical interlock so as toimprove performance thereof.

SUMMARY

According to a first aspect, a door interlock apparatus is provided. Thedoor interlock apparatus includes a body configured to couple to a firstone of a door and an enclosure door frame, the body having one or moreangled self-locating features; a locking protrusion extending from asurface of the body and configured to couple with the locking protrusionof an interlock mechanism; and a misalignment-accommodating mechanismconfigured and adapted to allow motion of the body.

According to a further aspect, a door interlock assembly is provided.The door interlock assembly includes a door interlock apparatus having abody configured to couple to a first one of a door and a enclosurestructure, the body having one or more angled self-locating features, alocking protrusion extending from the body, a misalignment-accommodatingmechanism configured to allow motion of the body; and an interlockmechanism configured to couple to a second one of the door and theenclosure structure, the interlock mechanism having a locking memberconfigured to couple with the locking protrusion.

According to a further aspect, an electrical component enclosure isprovided. The electrical component enclosure includes an enclosurestructure having an enclosure door frame; a door hinged to the enclosurestructure; and a door interlock apparatus having a body configured tocouple to a first one of the door and the enclosure structure, the bodyhaving one or more angled self-locating features, a locking protrusionextending from the body, a misalignment-accommodating mechanismconfigured to allow motion of the body; and an interlock mechanismconfigured to couple to a second one of the door and the enclosurestructure, the interlock mechanism having a locking member configured tocouple with the locking protrusion.

According to still another aspect, a method of operating a doorinterlock assembly is provided. The method includes providing a doorhinged to an enclosure structure; providing a door interlock apparatushaving a body coupled to a first one of the door and the enclosurestructure, the body having one or more angled self-locating features, alocking protrusion, and a misalignment-accommodating mechanism;providing an interlock mechanism coupled to another one of the door andthe enclosure structure, the interlock mechanism having a locking membercoupleable with the locking protrusion; and closing the door andengaging the locking member with one of the angled self-locatingfeatures causing movement of the body wherein themisalignment-accommodating mechanism allows the movement of the body soas to align the locking protrusion with the locking member.

Still other aspects, features, and advantages of the invention may bereadily apparent from the following detailed description wherein anumber of example embodiments and implementations are described andillustrated, including the best mode contemplated for carrying out theinvention. The invention may also be capable of other and differentembodiments, and its several details may be modified in variousrespects, all without departing from the scope of the invention.Accordingly, the drawings and descriptions are to be regarded asillustrative in nature, and not as restrictive. The drawings are notnecessarily drawn to scale. The invention covers all modifications,equivalents, and alternatives falling within the scope of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A illustrates a partial perspective view of an electricalcomponent enclosure including an improved door interlock apparatusaccording to embodiments.

FIG. 1B illustrates a full perspective view of an electrical componentenclosure including an improved door interlock apparatus.

FIGS. 1C and 1D illustrate front and rear perspective views of a door ofan enclosure including an improved door interlock apparatus according toembodiments.

FIG. 2A illustrates a perspective view of an improved door interlockapparatus according to embodiments.

FIGS. 2B and 2C illustrate front and rear perspective views of a body ofa door interlock apparatus according to embodiments.

FIG. 2D illustrates a front plan view of a slider of a door interlockapparatus according to embodiments.

FIG. 2E illustrates an exploded view of various components of a doorinterlock apparatus according to embodiments.

FIG. 3A illustrates a perspective view of an interlock mechanismaccording to embodiments.

FIG. 3B illustrates a partial side view of a door interlock assemblywith the door opened according to embodiments.

FIG. 3C illustrates a partial side view of a door interlock assemblywith the door closed according to embodiments.

FIG. 3D illustrates a partial side view of a door interlock assemblywith the door closed and interlocked according to embodiments.

FIG. 4 illustrates a method of operating a door interlock assemblyaccording to embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to the example embodiments of thisdisclosure, which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

The aforementioned problem of a mechanical interlock that does notalways function properly involves misalignment of the locking protrusionand the locking member of the mechanical interlock. The misalignment maybe due to tolerance stack-ups, initial factory assembly, distortion dueto transportation, installation, installation and assembly at the finallocation, and/or door hinge wear. However, such misalignment may make itdifficult to close the mechanical interlock. In particular, the weldedpin may be so misaligned that door closing is difficult. Accordingly,embodiments of the present invention improve the mechanical interlockand facilitate easy door closing and interlocking. In particular,embodiments of the invention comprising a door interlock apparatus thatimprove an orientation and alignment of a locking protrusion with alocking member of the interlock mechanism. As such, interlock latchingis accomplished more seamlessly and is forgiving of misalignment.Moreover, embodiments also allow rapid replacement of the door interlockapparatus, if necessary.

Thus, in one or more aspects, a door interlock apparatus, is providedhaving a body configured to couple to a door or an enclosure structure(e.g., door frame). The body has one or more angled self-locatingfeatures, and a locking protrusion extends from the body. Amisalignment-accommodating mechanism is configured to allow motion ofthe body relative to the component it is coupled to (e.g., door or anenclosure structure). The door interlock apparatus cooperates with aconventional interlock mechanism to allow rapid closing and interlockingof the door. The interlock mechanism couples to the other of the doorand the enclosure structure, and has a locking member that couples withthe locking protrusion to provide the door interlocking feature. Uponclosing the door and engaging the locking member with one of the angledself-locating features, movement of the body is caused along the door orenclosure wherein the misalignment-accommodating mechanism allows thebody to move in order to properly align the locking protrusion with thelocking member. In this way, substantial initial misalignment may bepresent due to tolerance stack-ups, initial factory assembly,transportation, assembly and installation at the final destination,and/or wear and rapid closing and interlocking may still beaccomplished.

Electrical component enclosures including the door interlock apparatus,door interlock assemblies, and methods of operating a door interlockassembly are provided, as will be explained in greater detail below inconnection with FIGS. 1A-4 herein.

FIGS. 1A-1D illustrate an electrical component enclosure 100 andcomponents thereof that may be used to contain one or more electricalcomponents, such as low-voltage, medium-voltage, or high-voltageelectrical components, such as an electrical contactor, load breakswitch, or other switch (e.g., a high-voltage switch). Other low-,medium- or high-voltage electrical components may be contained withinthe electrical component enclosure 100, as well. Electrical componentenclosure 100 may include a door interlock assembly 101 operative tointerlock a door 106 to an enclosure structure 104 of the electricalcomponent enclosure 100. The enclosure structure 104 may have variouswalls forming an enclosed space that contains an electrical component.The walls may include side walls 104W1, 104W2, rear wall 104W3, top wall104W4, bottom wall (not shown), and front wall 104W5 including anenclosure door frame 104F defining an opening that is closed by the door106. The door frame 104F may be a reinforced area of the enclosurestructure 104, or may simply be a front wall structure surrounding theopening closed by the door 106. Door 106 may overlap the opening. Thedoor 106 may be hinged to the enclosure structure 104, such as by one ormore hinges 104H such that upon opening or closing, the door rotatesaway from or towards the opening, respectively.

The door interlock assembly 101 includes a door interlock apparatus 108and an interlock mechanism 111, wherein the interlock mechanism 111interlocks with the door interlock apparatus 108. The door interlockapparatus 108 may be configured to couple to a first one of the door 106and the enclosure structure (e.g., enclosure door frame 104F). Theinterlock mechanism 111 may be configured to couple to a second one ofthe door 106 and the enclosure door frame 104F. In the depictedembodiment, the door interlock apparatus 108 is coupled to a door 106 ofthe electrical component enclosure 100, and the interlock mechanism 111is coupled to the enclosure structure 104 (e.g., to the enclosure doorframe 104F). However, this construction may be reversed in someembodiments wherein the door interlock apparatus 108 may be coupled tothe enclosure structure 104, and the interlock mechanism 111 may becoupled to the door 106. The interlock mechanism 111 may comprise aconventional interlock mechanism, such as a model A67-009-A3 interlockavailable from Powercon Corp. Of Severn, Md. Other types of interlockmechanisms 111 may be used. The interlock mechanism 111 operates with aload break switch (not shown) to cut power to the electricalcomponent(s) housed within the electrical component enclosure 100 whenthe handle of the interlock mechanism 111 is opened.

As best shown in FIGS. 2A-2E, the door interlock apparatus 108 includesa body 210 configured to couple to a first one of the door 106 and theenclosure 104 (e.g., the enclosure door frame 104F). The body 210 may bea block of rigid material, such as aluminum, although the body 210 maybe a non-metal material such as a plastic material in some embodiments.Other suitably rigid materials may be used. The body 210 may have alength of between about 75 mm and about 175 mm, and about 125 mm in someembodiments; a width of about 15-50 mm, and about 25 in someembodiments; and a thickness of between about 20 mm and about 40 mm, andabout 25 mm in some embodiments. Other body dimensions may be used. Thebody 210 may have one or more angled self-locating features 212 formedtherein. Further, the door interlock apparatus 108 has a lockingprotrusion 214 extending from a surface of the body 210. Door interlockapparatus 108 has a misalignment-accommodating mechanism 216 configuredto allow motion of the body 210. The motion may be along a direction 215(e.g., generally vertical) that is co-parallel with a door hinge axis115 (FIG. 1A). For example, the motion may be along the door frame 106F.

In the depicted embodiment, the one or more angled self-locatingfeatures 212 comprise engagement surfaces 212U, 212L that may be angledat an angle 217 of between about 45 degrees and 80 degrees to oneanother, and about 66 degrees as shown. In particular, the angledself-locating features 212 may comprise non-parallel engagement surfaces212U, 212L. As shown, the non-parallel engagement surfaces 212U, 212Lare positioned on opposite sides of the locking protrusion 214. At leastone of the surfaces (e.g., 212U) may be angled at more than a fewdegrees from the horizontal so as to form a ramp.

The locking protrusion 214 may be configured as and comprise a rigidcylindrical member, such as a steel pin, that may be press fitted into ahole 210H formed in the body 210, such that the locking protrusion 214extends from a surface 210S of the body 210 within a recess 218 formedin the body 210. The locking protrusion 214 may be integral with thebody in some embodiments. For example, the body 210 and lockingprotrusion 214 may be integrally formed, such as by casting, forging, ormolding. In some embodiments, the body 210 may be plastic and thelocking protrusion 214 may be metallic. The recess 218 may have a depth“d” of between about 10 mm and about 25 mm, for example. Other depthsmay be used. The recess 218 may form the angled self-locating features212, which may be non-parallel surfaces. The engagement surfaces 212U,212L may be provided at roughly right angles to the surface 210S.

The recess 218 may thus be configured in a manner that has a wideropening away from the locking protrusion 214, and wherein the recess 218height gets narrower nearer to the locking protrusion 214. Radiusedcorners 218R may be provided on the mouth of the recess 218. The recess218 may include an end pocket 218P provided at a location opposite ofthe mouth that may interface with the locking member of the interlockmechanism 111.

The misalignment-accommodating mechanism 216 may be configured as, andcomprise, one or more slots 220U, 220L formed in the body 210 and one ormore sliders 224U, 224L received in the one or more slots 220U, 220L. Inthe depicted embodiment, two slots 220U, 220L are provided with a lengthof the slots (e.g., the longer dimension) being aligned with a length ofthe door frame 106F. The slots 220U, 220L may each include a rearportion 222U, 222L that interfaces with a pilot 224P formed on thesliders 224U, 224L (See representative slide 224U in FIG. 2D), and afront portion 223U, 223L that is larger than the rear portions 222U,222L and recessed to accept a head 224H of the slider 224U therein. Thesliders 224U, 224L may include a threaded portion 224T thereon that maybe threaded into captured nuts 225 provided on the door frame 106F, forexample.

In the depicted embodiment, the sliders 224 comprise shoulder screws.However, this structure may be replaced with a conventional screw andcylindrical bushing. In the depicted embodiment, themisalignment-accommodating mechanism 216 comprises the first slot 220Uand the second slot 220L formed in the body 210, and a first slider 224Uslideably received in the first slot 220U and a second slider 224Lslideably received in the second slot 220L.

In an alternative embodiment, the misalignment-accommodating mechanismmay include slots formed on the enclosure door frame and the sliders maybe mounted into a side of the body opposite from the locking projectionand slide in the slots. The sliders may be integral with the body inanother embodiment. In yet other embodiments, only a single slider maybe used, whereas the single slider may include rotation-retaining means,such as one or more planar surfaces that ride on one or more sides of asingle slot to restrict the body 210 to motion along direction 215(e.g., generally vertical motion as shown). In other embodiments, theorientation of the body 210 and the one or more slots 220U, 220L may besuch that the motion direction is other than along the door frame 106F(e.g., at an angle to the door frame 106F along the long side of thedoor 106). Any suitable mechanism for facilitating limited slidingmotion of the body 210 may be used. In some embodiments, one or moresprings may spring bias the body 210. For example, one or more springsmay act between the one or more sliders 224U, 224L and the body 210, orbetween the body 210 and the door frame 106F (or enclosure structure ifattached thereto) to spring bias the body 210. The spring biasing maycenter the body 210 within its motion range, or bias the body 210 to oneend of the motion range. Adding spring biasing may allow the interlockapparatus 108 to be installed in other than a vertical orientationshown. For example, the interlock apparatus 108 may be installed along ahorizontal door edge.

The rear portions 222U, 222L of the slots 220U, 220L may be sizedrelative to the height and diameter of the pilot 224P such that the body210 may freely slide along the direction 215 within a large alignmentzone, yet is restrained from any significant motion in the directions226, 228. For example, the slots 220U, 220L may be dimensioned alongtheir respective lengths to allow the body 210 to move relative to thedoor frame 106F in the direction 215 substantially more than in theother directions 226, 228. The misalignment-accommodating mechanism 216may allow door misalignment in the direction 215 that may be greaterthan about 10 mm, or even greater than 15 mm, and between 10 mm and 30mm in some embodiments. The misalignment-accommodating mechanism 216 maybe configured to allow motion of the body 210 of up to about 20 mm alongdirection 215 in some embodiments. Other motion amounts may be allowed.

In accordance with another aspect, the body 210 may be constrained bythe misalignment-accommodating mechanism 216 in the directions 226, 228such that motions in these directions are less than about 12 mm, or evenless than about 5 mm, and between 3 mm and 12 mm in some embodiments.

FIG. 3A illustrates an interlock mechanism 111 that is configured tocouple to a second one of the door 106 and the enclosure structure 104(e.g., to enclosure door frame 104F) via fasteners 329. The interlockmechanism 111 has a locking member 330 that is configured tomechanically couple with the locking protrusion 214. The operation ofthe door interlock assembly 101 is shown in FIGS. 3B and 3C. Inparticular, the door interlock apparatus 108 is shown coupled to thedoor frame 106F. When the door is open (FIG. 3B), themisalignment-accommodating mechanism 216 provides a configuration wherethe sliders 224U, 224L are located at the top of the slots 220U, 220Lvia the force of gravity. Thus, the body 210 is offset from a roughlycentered position. As such, some misalignment “m” between the lockingprotrusion 214 and the locking member 330 of the interlock mechanism 111exists, even for a perfectly aligned door 106.

FIG. 3C illustrates the door interlock assembly 101 as the door 106 isbeing a closed. As the door 106 is closed, the outer surface (e.g.,cylindrical surface) of the locking member 330 contacts a top one 212Uof the one or more angled self-locating features 212, and thus raisesthe body 210 relative to the door frame 106F. The same operatingprinciple holds true when the door 106 is misaligned within the lockingmember 330 of the interlock mechanism 111. Any misalignment isaccommodated by the door interlock assembly 101. In particular, the doorinterlock apparatus 108 may allow motion of the body 210 in thedirection 215 that may be greater than about 10 mm, or even greater than15 mm, and between 10 mm and 30 mm in some embodiments.

FIG. 4 illustrates a method 400 of operating a door interlock assembly(e.g., door interlock assembly 101) in accordance with one or moreembodiments. Method 400 includes, at block 402, providing a door (e.g.,door 106) hinged to an enclosure structure (e.g., enclosure structure104), and in block 404, providing a door interlock apparatus (e.g., doorinterlock apparatus 108) having a body (e.g., body 110) coupled to afirst one of the door and the enclosure structure, the body having oneor more angled self-locating features (e.g., one or more angledself-locating features 212), a locking protrusion (e.g., lockingprotrusion 214), and a misalignment-accommodating mechanism (e.g.,misalignment-accommodating mechanism 216). In block 406, the method 400involves providing an interlock mechanism (e.g., interlock mechanism111), coupled to another one (e.g., the other one) of the door and theenclosure structure, the interlock mechanism having a locking member(e.g., locking member 330) that is coupleable with the lockingprotrusion. In block 408, the method 400 of operating a door interlockassembly includes closing the door and engaging the locking member withone of the angled self-locating features causing movement of the bodywherein the misalignment-accommodating mechanism allows the movement ofthe body so as to align the locking protrusion with the locking member.

As is illustrated in FIG. 3B, the door interlock apparatus 108 may beinstalled low enough on the door 106 (or optionally to the enclosurestructure 104) and include motion capability sufficient to anticipateand accommodate a maximum amount of misalignment (e.g., due to assembly,tolerance stack-ups, and wear) and still vertically align the lockingprotrusion 214 with the locking member 330. In FIG. 3D, the lockingprotrusion 214 of the door interlock apparatus 108 is shown captured bythe locking member 330, such that the door 106 is interlocked and cannotbe opened. The locking member 330 may include a notch that receives thelocking protrusion 214 and is rotated responsive to throwing the handle331 of the interlock mechanism 111. This locks the door 106 to theenclosure structure 104 and also actuated and electrical switch (notshown) electrically coupled to the one or more electrical componentscontained in the electrical component enclosure 100. Any suitable shapeof the locking member 330 may be used, as long as the locking member 330will capture the locking protrusion 214. In some embodiments, anInterlock mechanism 111 having a linearly-moving locking member may beused. The linearly-moving locking member may translate in front of thelocking protrusion 214 upon actuation of a handle (like handle 331) ofthe Interlock mechanism. In some embodiments, the door interlockapparatus 108 may be mounted on or be part of an Interlock mechanism,which may be considered as being on part of the enclosure structure.

It should be understood that the above process blocks of method 400 maybe executed or performed in an order or sequence not limited to theorder and sequence shown and described. Also, some of the above blocksmay be executed or performed substantially simultaneously or in parallelwhere appropriate or desired. For example, in some embodiments, blocks402, 404, and 406 may be performed in reverse order or in parallel orsubstantially simultaneously.

Note that a person of ordinary skill in the art should readilyappreciate that the invention described herein is susceptible of broadutility and application. Many embodiments and adaptations of theinvention other than those described herein, as well as many variations,modifications, and equivalent arrangements, will be apparent from, orreasonably suggested by, the invention and the foregoing descriptionthereof, without departing from the substance or scope of the invention.Accordingly, while the invention has been described herein in detail inrelation to specific embodiments, it is to be understood that thisdisclosure is only illustrative and presents examples of the inventionand is made merely for purposes of providing a full and enablingdisclosure of the invention. This disclosure is not intended to limitthe invention to the particular apparatus, assemblies or methodsdisclosed, but, to the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the scope ofthe invention.

What is claimed is:
 1. A method of operating a door interlock assembly,comprising the steps of: closing a hinged door towards an enclosurestructure; contacting a locking member to a body of an interlockapparatus; sliding the locking member along the interior surface of acavity of the body towards a downward direction and away from a point ofcontact when the locking member contacts the body; and moving the bodysubstantially in a vertical direction when the locking member contactsthe body.
 2. The method of claim 1, wherein the step of closing thehinged door towards the enclosure structure further comprises the stepof moving the door in a radial direction.
 3. The method of claim 1,wherein the step of closing the hinged door towards the enclosurestructure further comprises the step of pivoting the door about a hingeconnecting the door to the enclosure structure.
 4. The method of claim1, further comprising the step of contacting the locking protrusion withthe locking member.
 5. The method of claim 4, wherein the step ofcontacting the locking protrusion with the locking member comprises thestep of engulfing the locking protrusion with the locking member.
 6. Themethod of claim 5, further comprising the step of stopping the movementof the locking member when the locking protrusion and the locking membermake contact.
 7. The method of claim 4, further comprising the step ofsliding the body in substantially a vertical direction along the lengthof one or more slots in the body when the locking member and theprotrusion make contact.
 8. The method of claim 7, wherein the step ofsliding the body in substantially a vertical direction comprises thestep of sliding the body on one or more sliders along the interiorsurface of one or more slots.
 9. The method of claim 8, furthercomprising the step of stopping the movement of the body substantiallyupward when the slider reaches an upper end of the one or more slots.10. The method of claim 9, wherein the step of sliding the body insubstantially a vertical direction comprises the step of moving the bodyincrementally upwards as the locking member moves incrementallytransverse to the upward movement of the body.
 11. The method of claim9, wherein the step of sliding the body in substantially a verticaldirection comprises the step of displacing the body upwards to adistance proportional to the vertical length of the locking member. 12.The method of claim 4, further comprising the step rotating the lockingmember about the locking protrusion.
 13. The method of claim 12, furthercomprising the step of securing the door to the enclosure structureafter rotating the locking member about the locking protrusion.
 14. Amethod of operating a door interlock assembly, comprising the steps of:closing a hinged door towards an enclosure structure; contacting alocking member to a body of an interlock apparatus; sliding the lockingmember along the interior surface of a cavity of the body towards adownward direction and away from a point of contact when the lockingmember contacts the body; sliding the body in substantially a verticaldirection along the length of one or more slots in the body when thelocking member and the protrusion make contact; contacting the lockingprotrusion with the locking member; and moving the body substantially ina vertical direction when the locking member contacts the body.
 15. Themethod of claim 14, wherein the step of contacting the lockingprotrusion with the locking member comprises the step of engulfing thelocking protrusion with the locking member.
 16. The method of claim 14,wherein the step of sliding the body in substantially a verticaldirection comprises the step of sliding the body on one or more slidersalong the interior surface of one or more slots.
 17. The method of claim16, further comprising the step of stopping the movement of the bodysubstantially upward when the slider reaches an upper end of the one ormore slots.
 18. The method of claim 17, wherein the step of sliding thebody in substantially a vertical direction comprises the step of movingthe body incrementally upwards as the locking member moves incrementallytransverse to the upward movement of the body.
 19. The method of claim18, further comprising the steps of: displacing the body upwards to adistance proportional to the vertical length of the locking member;rotating the locking member about the locking protrusion; and securingthe door to the enclosure structure after rotating the locking memberabout the locking protrusion.
 20. A method of operating a door interlockassembly, comprising the steps of: closing a hinged door towards anenclosure structure; pivoting the door about a hinge connecting the doorto the enclosure structure and in a radial direction; contacting alocking member to a body of an interlock apparatus; sliding the lockingmember along the interior surface of a cavity of the body towards adownward direction and away from a point of contact when the lockingmember contacts the body; sliding the body in substantially a verticaldirection along the length of one or more slots in the body when thelocking member and the protrusion make contact; moving the bodyincrementally upwards as the locking member moves incrementallytransverse to the vertical movement of the body; contacting the lockingprotrusion with the locking member; and moving the body substantially ina vertical direction when the locking member contacts the body.